Process for producing oxidation



Patented Dec. 31, 1935 UNITED STATES PROCESS FOR PRODUCING OXIDATIONPRODUCTS OF CASTOR- OIL AND THE LIKE Melvin no Groote, St. Louis, andBernhard Keiser, Webster Groves, Mo., assignors to Tretolite Company,Webster Groves, Mo., a corporation of Missouri No Drawing. ApplicationJanuary 30, 1935, Serial No. 4,089

5Clairns.

This invention relates to the manufacture of certain oxidation productsof castor oil and the like, i. e., products obtained or produced by theoxidation of castor oil or castor oil' bodies at a 5 relatively lowtemperature and at a pressure of not over 125 lbs.

The object of our invention is to provide a novel process for producingproducts or materials of the kind mentioned. Briefly described, ourproc- 1 ess consists in subjecting castor oil or thelike to pressureoxidation in the presence of an autooxidizer-catalyst consisting of anoctadecadiene- 9,11-acid-1 body.

In order to clearly define and explain our in- 15 vention, it will benecessary to refer briefly to prior processes or procedures that havebeen employed or suggested to obtain products or materials produced bythe oxidation or blowing of various oils with dry or moist air ororwgen. In

. 20 a general way, animal or vegetable oils may be divided into fivegeneral classes, based on their susceptibility to oxidation reactions,involving the use of air or oxygen. The first of the above mentionedclasses includes such materials as 25 stearic acid, which does notcontain an ethylene linkage and is not saturated. Such a fatty body isnot susceptible to oxidation by the conventional methods.

The. second of the above-mentioned classes is 30 unique, in thatthe onlymaterial or materials of said class that are commercially available, arecastor oil and simple castor'oil' derivatives, such as ricinoleic acid,or poly-ricinoleic acid. Castor oil is characterized by the fact that itmay be 35 exposed to air or oxygen for a long time in a very thin film,without absorbing any oxygen. In other words, notwithstanding the factthat castor oil contains an ethylene linkage, still, so far as reactionsat ordinary temperatures or pressures 40 are concerned, it is hardlymore reactive towards air or oxygen than if it were a saturated fattybody, such as stearin, or stearic acid.

' The third of the above-mentioned classes of materials includes theso-called non-drying oils.

45 These oils, such as oleic acid, olein, etc. are nondrying in thesense that they do not absorb oxygen and dry quickly enough to produce apaint film. However, they are differentiated from castor oil, in that afilm exposed to air or oxygen at ordinary 50 temperatures for a periodof time, will oxidize slowly but rather completely.

The fourth of the above-mentioned classes of materials consists of theso-called semi-drying oils, such as cotton seed oil, and certain marine55 oils which are more reactive than oleic acid or the like, but not soreactive as the true drying oils, which are characterized, for example,by linseed oil.

The fifth of the above-mentioned classes of materials comprises the truedrying oils which absorb air or oxygen rapidly enough to produce a paintfilm when exposed in a thin layer and which may absorb oxygen rapidlyenough at ordinary temperatures to cause spontaneous combustion.

It is common practice to blow or oxidize various fatty materials of thekind above enumerated to produce materials intended for use in variousarts. Linseed oil, for example, is oxidized to produce a solid, such aslinoxyn. Certain oils are oxidized to produce plasticizers for use inthe manufacture of artificial leather and the like. Certain oils areoxidized, so as to give miscibility with petroleum oils to produceblended lubricating oils, and certain oils are oxidized to produce aproduct of certain desired characteristics employed in the manufactureof varnish and the like.

It is well known that an oxidation process or procedure, which may besuitable for one of the five general classes of oils, previouslymentioned, 5 may not be suitable for a different class. For example, theprocess used to oxidize the linseed oil type of oil are usuallyineffective in regard to castor oil, or even in regard to oleic acid andthe processes employed for oxidizing olive oil or rape seed oil, may beentirely too drastic for use on linseed oil. Moreover,-in the oxidationof oils, particularly linseed oil, and certain marine oils, theresultant product depends entirely on the mode of treatment. Marineoils, for example, may be oxidized primarily to decolorize or deodorizethe oil, and such oxidation is intended solely to oxidize or destroy theimpurities so as to permit the oil under treatment to remain more orless unchanged.

In the co-pending application for patent of the present applicantsjointly with Arthur'F. Wirtel, Serial No. 752,718, filed November 12,1934, there is disclosed a process for producing blown oils, thatinvolves subjecting fatty bodies to oxidation after admixture with arelatively small amount of a vegetable oil of the true drying type, withor withouta small amount of a fat splitting sul fonic acid.

. In another co-pending application for patent filed by theabove-mentioned applicants, Serial No. 760,031, filed December 31, 1934,there is disclosed a process for producing poly keto fatty bodies orpoly aldehydic fatty bodies, that involves the oxidation of castor oil,polyricinoleic 5 or ricinoleic acidunder pressure at a relatively lowtemperature. The temperature employed in the said process is below thetemperature at which castor oil can be oxidized under ordinaryconditions, for instance, it is less than 150 C.,- and generallyspeaking, the oxidation is conducted at approximately 120 C. Thepressure employed in the said process varies from 25 to 125 lbs. gaugepressure, the pressure most conveniently employed being about 45 lbs. Inthe above-mentionedlow temperature-low pressure process, the reactiontakes place primarily, due to the presence of a catalyst, which consistsof a true drying oil, such as linseed oil. Usually, the castor oil body,before being subjected to low temperature pressure oxidation, is mixedwith not over 20% of linseed oil. In the absense of linseed oil, eitherthe reaction does not take place, or the reaction takes place so slowlythat such oxidation procedure would not be feasible or economical, ormight even produce some other compound. In a general way, oxidation of amixture of castor oil and 10% of linseed oil takes place very readily ata temperature of C. and 45 lbs. air pressure. Such reaction may becompleted in ten hours or less, depending upon the size of pressurevessel used during oxidation. The air,

employed may be dried or moist, in the sense that it may carry itsnormal moisture content.

Castor oil is differentiated from other oils and other fatty materialsin regard to its reaction towards oxidation in various manners. As hasbeen previously pointed out, castor oil, although containing an ethylenelinkage, does not oxidize under ordinary conditions, even after longexposure in a thin film. For this reason it is even less reactive thanordinary so-called non-drying oils. Its action is more analogous, so faras oxidation goes, to inert oils of the stearic acid type. Castor oil orricinoleic acid or the related esters, such as the ethyl, methyl,propyl, or butyl ester, are further distinguished by the fact that thematerials contain an alcoholiform hydroxyl, and thus, ricinoleic acid isnot only a fatty acid, but is also a fatty alcohol and is more properlydescribed, perhaps, as an alcohol acid. Such materials which arecharacterized by the presence of a ricinoleic acid radical will bereferred to as castor oil bodies because they are invariably derivedfrom castor oil as an original raw material. It is a secondary alcohol,and as is well known, the oxidation of a secondary alcohol produces aketone, and thus, it is believed that the cautious oxidation of castoroil in the manner described in the said De Groote et al. applicationSerial No. 760,031, results in the formation of keto acids or keto acidbodies, and particularly, in the formation of poly keto acid bodies. Itis true that the fatty bodies thus obtained may actually be aldehydicfatty bodies and not keto fatty bodies, although both are characterizedby a reactive carbonyl radical.

. We believe that the linseed oil present during the oxidation of.castor oil, as described in the said De Groote et al. application SerialNo.760,- 031, acts in part as an auto-oxidizer, and acts in part as anoxidation catalyst. Without attempting to elaborate as to the workingmechanism of an auto-oxidizer (see Catalysis in Organic Chemistry,Sabatier & Reid, 1923, pages 46 and 47), it i suiiicient to state thatan auto-oxidizer,

from the reaction which it has caused. On the other hand, the additionof linseed oil, for example, to castor oil, does not hasten the reactiondirectly in proportion to the added linseed oil. For instance, an 8020mixture does not necessarily oxidize twice as rapidly as a 90-10mixture. Furthermore, it is well known that some 5 auto-oxidizers may beentirely regenerated and again serve as a carrier of free oxygen to theoxidizable substance. It is further possible that the oxidation oflinseed oil or any other added material may result in certain newproducts, 10 which, in turn, may act as auto-oxidizers or as oxidationcatalysts. Accordingly, in the said De Groote et al. application SerialNo. 760,031, the linseed oil used in the process is referred to as anauto-oxidizer catalyst, with the under- 15 standing that the reactionmay be promoted by the linseed oil or some product therefrom actingeither in the capacity of an auto-oxidizer or in the capacity of anoxidation catalyst, orin a dual capacity. As far as the commercialopera- 20 tion of such oxidation reactions are concerned, it is obviousthat these materials may be added in the designated proportion and themixture submitted to oxidation under the described conditions, so as toobtain the advantages described, 25

without reference as to the theoretical aspects of the oxidation stepitself.

We have found that while certain materials will act asauto-oxidizer-catalysts, so as to promote the cautious and controlledoxidation of 30 castor oil or the like at relatively low temperaturesand under moderate pressures of the kind described, there does notappear to be any general characteristic whereby this particularpropertyof a substance may be anticipated. Materials which may serve asauto-oxidizers or catalysts in regard to other reactions may not haveany efiect in hastening'the oxidation of castor oil under the describedconditions. Likewise, materials which may be effective in hastening the40 oxidation of castor oil, under the conditions described, may not beeffective in other reactions where it is known that'some otherauto-oxidizercatalysts may be employed. At least; at the present timeand in regard to the low temperature 45 pressure oxidation of castor oilbodies, it appears that this peculiar property is that of an individualsubstance or compound, and cannot be ascribed to a class broadly, as faraswe are now aware.

We have also found the octadecadiene-9,11- acid-1 is a very effectiveauto-oxidizer-catalyst, when employed in a low temperature pressureoxidation of castor oil bodies. Accordingly, we have devised a novelprocess for producing certain ox- 5 idation products of castor oil andthe like that involves subjecting a castor oil body, such as castor oil,ricinoleic acid or polyricinoleic acid, to oxidation at a temperature-ofnot over 140 C. and at a pressure of not over lbs. in the presence 60 ofoctadecadiene-9,11-acid 1. Octadecacliene- 9,11-acid-1 bodies arederived by the dehydration of ricinoleic acid or its esters and may bederived by the dehydration of triricinolein, i. e., the glyceride ofricinoleic acid. Obviously, instead of 65 the acid itself, one mayemploy the glyceride as the auto-oxidizer-catalyst, because the propertyis possessed by the long chain hydrocarbon radical and not by theglyceryl radical, because glycerol or ordinary glycerides, such as oliveoil, 7 do not have the property of hastening or otherwise efiectingoxidation. In practicing our process we prefer to use the glycerides ofoctadecadiene-9,11-acid-1 and they need not necessarily be pure, but maybe obtained in a semi-pure state 75 by the dehydration of castor oil.The manufacture of octadecadiene-9,l1-acid-1 or its glycerides isdescribed in U. S. Patent No. 1,920,585, to Ott and Schussler, datedAugust 1, 1933, and also in Holzol and Holzolersatz in Farbe und Lack,1929, page 154. In our process we use not over 20%, and preferably,approximately 10% of octadecadiene-9,1l-acid-l bodies, particularly theglyceride bodies obtained by the dehydration of castor oil, as anauto-oxidizer-catalyst in the low temperature pressure oxidation ofcastor oil, so as to produce oxidation products of the kind which appearto be poly keto or poly aldehydo fatty bodies. We prefer that theoxidation be conducted with air having its ordinary moisture content,and at a temperature of 120 and at a pressure of lbs.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. A process for the purpose described, characterized by substantiallyoxidizing, by means of a gasous, oxygen-containing medium, castor oil ata temperature within the range of approximately C. to 150 C. and at agauge pressure within the range of 25 to lbs. and using 10% to 20% byweight of octadecadiene-9,l1-acid-1 glyceride as anauto-oxidizer-catalyst.

2. A process for the purpose described, which consists in substantiallyoxidizing castor oil by means of air of normal moisture content at atemperature within the range of approximately 120 C. to C. and at agauge pressure within the range of 25 to 125 lbs. and using 10% to 20%,by weight, of octadecadiene9,11-acid-1 glyceride as anauto-oxidizer-catalylst.

3. A process for the purpose described, which consists in substantiallyoxidizing castor oil by 5 means of air of normal moisture content at atemperature of approximately 120 C. and under a gauge pressure of 45lbs. and using as an autooxidizer-catalyst, octadecadiene 9,11 acid 1glyceride obtained by dehydration of triricinolein, 10 saidoctadecadiene glyceride being equivalent in weight to 10% of the castoroil being oxidized.

4. A process for the purpose described, characterized by substantiallyoxidizing, by means of a gaseous, oxygen-containing medium, a castor 15oil body at a temperature within the range of approximately 120 C. to150 C. and at a gauge pressure within the range of 25 to 125 lbs. andusing 10% to 20%, by weight, of an octadecadiene-9,1l-acid-1 body as anauto-oxidizer-cata- 2O lyst, said castor oil body being characterized bythe presence of a ricinoleic acid radical.

5. A process for the purpose described, characterized by substantiallyoxidizing, by means of a gaseous, oxygen-containing medium, castor oil,25 at a temperature within the range of approximately 120 C. to 150 C.and at a gauge pressure within the range of 25 lbs. to 125 lbs. andusing 10% to 20%, by weight, of an octadecadiene- 9,1l-acid-1 body as anauto-oxidizer-catalyst. -30

MELVIN DE GROOTE. BERNHARD KEISER.

